The following U.S. patents comprise the closest known prior art:
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Since the inception of wire fences, and in particular barbed wire fences, it has been recognized that the wire strands that comprise the fence often become slack and loose. Slack wire seriously degrades the ability of the fence to retain livestock or to repel intruders. The wire strands become slack due to the fact that the metal which forms the strands will yield in plastic fashion under tension, thus elongating and sagging. This effect may be caused by livestock pushing against the wire strands or against the fence posts. In any case it is often necessary to maintain wire fences and to take up the slack which frequently forms in the wire strands.
There are known in the prior art many devices for removing slack in the strands of a wire fence. Such devices generally comprise a tool for twisting or wrapping the fence strands to remove the slack therein. In addition, it is usually necessary to retain the twisted or wrapped portion in the fence strand by applying a wire tie or clip to the twisted portion. Experience has shown that the use of such tools often results in breaking the wire strands of the fence. This is usually due to the fact that the twisted or wrapped portion of the fence strand is highly stressed and incapable of supporting the tension in the strand. Even if the twisted or crimped fence wire portion does not break immediately, it is seriously weakened and likely to fail and break under the slightest additional stress. Also, many of the prior art tools are designed to impart multiple twists or wraps to the fence strands, thus exacerbating this problem. Furthermore, it is often difficult to manipulate the prior art fence tightening tools while at the same time applying the retaining wire or clip. When working with barbed wire fences, an individual must wear heavy protective gloves, making such a task quite laborious and difficult.